Contents xv
9.10 High-Slew-Rate Op Amps ........................................................ 397
9.10.1 One-Stage Op Amps . . . ................................................... 397
9.10.2 Two-Stage Op Amps ...................................................... 399
9.11 Power Supply Rejection .......................................................... 400
9.12 Noise in Op Amps ............................................................... 402
10 Stability and Frequency Compensation ....................................... 410
10.1 General Considerations .......................................................... 410
10.2 Multipole Systems ............................................................... 414
10.3 Phase Margin ................................................................... 416
10.4 Basic Frequency Compensation . . ................................................. 420
10.5 Compensation of Two-Stage Op Amps ............................................. 426
10.6 Slewing in Two-Stage Op Amps .................................................. 433
10.7 Other Compensation Techniques . ................................................. 436
10.8 Nyquist’s Stability Criterion ...................................................... 439
10.8.1 Motivation ............................................................... 439
10.8.2 Basic Concepts ........................................................... 440
10.8.3 Construction of Polar Plots ................................................ 442
10.8.4 Cauchy’s Principle ........................................................ 447
10.8.5 Nyquist’s Method ........................................................ 447
10.8.6 Systems with Poles at Origin .............................................. 450
10.8.7 Systems with Multiple 180
◦
Crossings ...................................... 454
11 Nanometer Design Studies .................................................... 459
11.1 Transistor Design Considerations . ................................................ 459
11.2 Deep-Submicron Effects ......................................................... 460
11.3 Transconductance Scaling ........................................................ 463
11.4 Transistor Design ................................................................ 466
11.4.1 Design for Given I
D
and V
DS,min
........................................... 466
11.4.2 Design for Given g
m
and I
D
............................................... 469
11.4.3 Design for Given g
m
and V
DS,min
........................................... 470
11.4.4 Design for a Given g
m
.................................................... 471
11.4.5 Choice of Channel Length ................................................. 472
11.5 Op Amp Design Examples ....................................................... 472
11.5.1 Telescopic Op Amp ....................................................... 473
11.5.2 Two-Stage Op Amp ....................................................... 487
11.6 High-Speed Amplifier............................................................ 495
11.6.1 General Considerations . . ................................................. 496
11.6.2 Op Amp Design .......................................................... 500
11.6.3 Closed-Loop Small-Signal Performance .................................... 501
11.6.4 Op Amp Scaling.......................................................... 502
11.6.5 Large-Signal Behavior . . .................................................. 505
11.7 Summary ....................................................................... 507